Demonstration Video: Handwriting recognition for maths!!!

Hi,

This will be the last time I bother you with this for a little while. I have produced a rather amateur video (4min) of what I think handwriting recognition for maths should look like. For the time being, I have named it MathPen.

What I want to know is: 1. how useful do you think MathPen would be for your personal work?
2. how useful do you think MathPen would be for others?3. is there any useful feature that should be included in MathPen?